This invention relates to fluid injecting and mixing devices and methods and, more particularly, but not by way of limitation, to such a device and method which will inject relatively low pressure fluids into relatively high pressure fluids.
Devices for mixing a lower pressure secondary fluid into a higher pressure primary fluid are known and are commercially available. Typical of such devices are jet pumps. Jet pumps are not injection devices but are ingestion or inspiration devices in that they create a vacuum and use the vacuum to pull the secondary fluid into the primary fluid. This is accomplished at a significant energy expenditure in the form of pressure loss. A typical jet pump drops or loses 30% or more of the inlet pressure of the primary fluid in ingesting the additive or secondary fluid and also loses a significant percentage of the fluid velocity in accomplishing the ingestion.
The devices and methods for injecting a relatively low pressure secondary fluid into a relatively high pressure primary fluid known to the applicant require either pumping or compressing the secondary fluid to the pressure of the primary fluid or reducing the pressure of the primary fluid, either of which requires a relatively high expenditure of energy.
Therefore, there is a need for an injection and mixing device and method which will mix a relatively low pressure secondary fluid with a relatively high pressure primary fluid at a greater energy efficiency. There is a need for such a device which will inject a relatively low pressure secondary fluid into a relative high pressure primary fluid, increase the mass flow of the fluid downstream of the injection point, and substantially maintain the fluid velocity, all at a relatively low energy loss in the overall recovered downstream mass flow. There is a need for such a device which may be used to cool a high temperature, pressurized primary fluid by injecting a cooler, relatively low pressure secondary fluid at a high energy efficiency. There is also a need for such a device which may be used to cool high temperature, high pressure primary fluids which contract when cooled, such as combustion gases, while adding mass to the primary fluid by injecting a relatively low pressure, cooler fluid into the thermally contracting primary fluid. There is also a need for such a device which may be used to improve the efficiency of pressure-driven engines and generators. There is also a need for such a device which is relatively inexpensive to manufacture and maintain.